Novel Q&P process, microstructure and mechanical properties of a 980 MPa grade hot-dip galvanized steel

doi:10.13251/j.issn.0254-6051.2021.11.022

Abstract

Abstract: A novel high-quenching-temperature quenching and partitioning (HQ&P) process was proposed to investigate the microstructure and mechanical properties of a 980 MPa grade C-Mn-Si-Al hot-dip galvanized steel by comparison with the conventional quenching and austempering (QAT) process. The results show that the desired duplex microstructure consisting of blocky ferrite, bainite, and some M/A islands is achieved in the tested steel. With the increase of annealing temperature during QAT process, the content of ferrite gradually decreases while the content of bainite increases. During the HQ&P process, the bainitic transformation occurs twice, which results in a more uniform microstructure with more bainite and a small amount of retained austenite. The best mechanical properties of the tested steel treated by HQ&P process are obtained with the tensile strength of 1005 MPa and the elongation of 26.1%.

Key words: hot-dip galvanized steel, dilatation curve, quenching and partitioning process, bainitic transformation, microstructure, mechanical properties

CLC Number:

TG142.1

Wang Kaitai, Xu Yunbo, Xu Bing, Gu Xingli, Wang Yuan, Li Jiayu, Ni Shenya, Gong Dianyao. Novel Q&P process, microstructure and mechanical properties of a 980 MPa grade hot-dip galvanized steel[J]. Heat Treatment of Metals, 2021, 46(11): 143-146.

References

[1]江海涛, 唐荻, 米振莉. 汽车用先进高强度钢的开发及应用进展[J]. 钢铁研究学报, 2007(8): 1-6.
Jiang Haitao, Tang Di, Mi Zhenli. Latest progress in development and application of advanced high strength steels for automobiles[J]. Journal of Iron and Steel Research, 2007(8): 1-6.
[2]汪志刚, 赵征志, 赵爱民, 等. 热处理工艺对冷轧热镀锌双相钢组织与性能的影响[J]. 钢铁, 2012, 47(2): 76-80.
Wang Zhigang, Zhao Zhengzhi, Zhao Aimin, et al. Effects of heat treatment process on microstructure and properties of hot-dip galvanized dual phase steel[J]. Iron and Steel, 2012, 47(2): 76-80.
[3]Wang Yu, Xu Yunbo, Liu Rendong, et al. Microstructure evolution and mechanical behavior of a novel hot-galvanized Q&P steel subjected to high-temperature short-time overaging treatment[J]. Materials Science and Engineering A, 2020, 789: 139665.
[4]刘靖宝, 王云阁, 夏明生, 等. 退火对980 MPa级镀锌双相钢组织和性能的影响[J]. 金属热处理, 2017, 42(12): 193-198.
Liu Jingbao, Wang Yunge, Xia Mingsheng, et al. Influence of annealing on microstructure and mechanical properties of 980 MPa galvanized dual phase steel[J]. Heat Treatment of Metals, 2017, 42(12): 193-198.
[5]Yu Gong, Anthony J De Ardo. A study of the microstructure and properties of dual-phase steels processed using a continuous galvanizing line simulation: The benefits of optimized hot and cold rolling and the addition of vanadium[C]//第十届中国钢铁年会暨第六届宝钢学术年会论文集III. 上海: 中国金属学会, 2015: 723-734.
[6]Daniel Gaude-Fugarolas, Pascal J Jacques. A new physical model for the kinetics of the bainite transformation[J]. ISIJ International, 2006, 46(5): 712-717.
[7]Gao Guhui, Zhang Han, Tan Zhunli, et al. A carbide-free bainite/martensite/austenite triplex steel with enhanced mechanical properties treated by a novel quenching-partitioning-tempering process[J]. Materials Science and Engineering A, 2013, 559: 165-169.
[8]周澍, 钟勇, 王利. 1000 MPa级高延伸率Q&P钢的实验室研究[J]. 宝钢技术, 2015(4): 51-56, 61.
Zhou Shu, Zhong Yong, Wang Li. Development of 1000 MPa grade quenched and partitioned steels with high elongation[J]. Baosteel Technology, 2015(4): 51-56, 61.

[1]	Wang Yudai, Liu Yang, Zhu Yanyan, Tian Xiangjun, Cheng Xu, Ran Xianzhe, Qian Tingting. Effect of heat treatment on microstructure homogeneity and tensile properties of hybrid fabricated AerMet100 ultra-high strength steel [J]. Heat Treatment of Metals, 2022, 47(4): 1-9.
[2]	Zhang Ziyan, Chen Jun, Chen Xiaoya, Li Quan'an, Liu Jianxin. Effect of solution and aging treatment on microstructure and corrosion resistance of Mg-4Sm-3Gd-0.5Zr alloy [J]. Heat Treatment of Metals, 2022, 47(4): 10-16.
[3]	Liang Enpu, Xu Le, Yang Yong, Wang Maoqiu. Effects of Al and Cu additions on microstructure and mechanical properties of 40CrNi3MoV steel [J]. Heat Treatment of Metals, 2022, 47(4): 17-23.
[4]	Qi Xiaoliang, Li Yan, Ding Wei, Zhao Zengwu. Effect of original microstructure of medium manganese TRIP steel containing Al on microstructure and mechanical properties after intercritical annealing [J]. Heat Treatment of Metals, 2022, 47(4): 24-29.
[5]	Chen Baoan, Zhang Jingyuan, Zhu Zhixiang, Han Yu, Pan Xuedong, Zhang Lei, Chen Suhong. Effect of chemical composition on microstructure and properties of high strength Al-Mg-Si alloy [J]. Heat Treatment of Metals, 2022, 47(4): 30-38.
[6]	Chen Dongjun, Li Guangyang, Liu Gang. Effect of aging treatment on microstructure and mechanical properties of AlSi9Cu3 HPDC aluminum alloy [J]. Heat Treatment of Metals, 2022, 47(4): 53-56.
[7]	Chen Liansheng, Zhang Luyou, Tian Yaqiang, Yang Zixuan, Li Hongbin, Pan Hongbo, Wei Yingli. CCT curves and microstructure and properties of low-carbon high strength marine steel [J]. Heat Treatment of Metals, 2022, 47(4): 63-68.
[8]	Jia Changyuan, Huo Yuanming, He Tao, Huo Cunlong, Liu Keran. High temperature tensile deformation behavior and microstructure evolution law of 40CrNiMo steel [J]. Heat Treatment of Metals, 2022, 47(4): 69-74.
[9]	Wang Yunlong, Yu Wei, Zhang Yi, Shi Jiaxin, Li Minghui. Effect of austenitizing temperature on isothermal transformation and mechanical properties of bainite steel [J]. Heat Treatment of Metals, 2022, 47(4): 80-85.
[10]	Liu Liyan, Bi Wenzhen, Wei Xicheng. Effect of Mn element on microstructure evolution of galvanized coating of hot stamping steel [J]. Heat Treatment of Metals, 2022, 47(4): 93-99.
[11]	Luo Zaibin, Fan Zize, Peng Zhen. Research progress of light-weight high-entropy alloys [J]. Heat Treatment of Metals, 2022, 47(4): 100-107.
[12]	Fu Xibin, Chen Zihao, Zhang Ke, Zhao Shiyu, Sun Xinjun, Zhu Zhenghai, Liang Xiaokai, Yong Qilong. Effect of quenching temperature on microstructure and mechanical properties of high Ti low alloy wear-resistant steel [J]. Heat Treatment of Metals, 2022, 47(4): 122-127.
[13]	Su Pengji, Ma Yonglin, Dong Lili, Yang Xuefeng. Effect of magnetic field pre-annealing on microstructure and texture of CGO steel [J]. Heat Treatment of Metals, 2022, 47(4): 128-132.
[14]	Li Li, Zeng Yan, Wu Xiaochun. Heat treatment process optimization for 4Cr5Mo2VCo steel [J]. Heat Treatment of Metals, 2022, 47(4): 133-140.
[15]	Lü Jiesheng, Song Zhigang, He Jianguo, Feng Han, Zheng Wenjie, Zhu Yuliang. Microstructure transformation and strengthening-plasticization mechanism of S32205 duplex stainless steel after cold rolling and annealing [J]. Heat Treatment of Metals, 2022, 47(4): 141-145.